7.9 oz. weight, 1-3/8" diameter, 3-1/8" long, 6mm output shaft. High performance AXI 2820/8 GOLD LINE Outrunner and high quality rc planetary gearbox PG 4/33 with 4 satellite gears. Unique combination of AXI outrunner and lightweight gearbox can spin an extremely large propeller (18.5 x 12 folding prop). AXI 2820/8 GOLD LINE with PG 4/33 is ideally suited to narrow fuselages in large sailplanes up to 4000 grams (8.8 pounds!). This power unit runs at a very high RPM and must never be run in a no-load condition. Use a high quality controller like Jeti Advance PLUS or Jeti SPIN. We also recommend using an AXI Cooler for AXI 2820 series motors (PM28006). For use with 4S Lipo battery, 55A controller, and an 18.5 x 12 prop.